CN102568440B

CN102568440B - Display device

Info

Publication number: CN102568440B
Application number: CN201110416790.8A
Authority: CN
Inventors: 山下淳一; 内野胜秀
Original assignee: Joled Inc
Current assignee: Joled Inc
Priority date: 2010-12-15
Filing date: 2011-12-14
Publication date: 2016-02-24
Anticipated expiration: 2031-12-14
Also published as: US8878753B2; US20120154352A1; JP5652188B2; JP2012128149A; CN102568440A

Abstract

Display device comprises: display board, and it comprises the display element with current drive-type luminous component and this display board shows image based on vision signal; And brightness correction unit, it corrects the brightness of described display element by correcting the gray-scale value of input signal and exporting calibrated input signal as vision signal when working as display board display image.Brightness correction unit comprises running time conversion factor retainer, reference operating time counter, accumulation reference operating time reservoir, datum curve reservoir, gradation correction value holder and video signal generator.

Description

Display device

Technical field

The disclosure relates to display device, relates more specifically to the display device of the rheological parameters' change with time of the brightness that can compensate display element.

Background technology

The display element with luminous component and the display device with such display element are well-known.Such as, there is the electroluminescence utilizing organic material (following, also abridge as EL) the display element of organic electroluminescent part (following, also organic EL display element is abbreviated as), drive with the display element of high brightness luminescence as by low voltage DC, cause attention.

Be similar to liquid crystal display, such as, in the display device (following, be also abbreviated as organic EL display) comprising organic electro-luminescent display unit, passive matrix and active matrix (activematrix) type as driving be well-known.This active array type has baroque shortcoming, but has the advantage that can strengthen brightness of image.The organic EL display element driven by driven with active matrix method comprises the luminous component be made up of the organic layer comprising luminescent layer and the driving circuit driving this luminous component.

(following as driving organic electroluminescent part, also be abbreviated as luminous component) circuit, such as, the driving circuit (being called 2Tr/1C driving circuit) of two transistors and a capacitor is comprised as everyone knows from JP-A-2007-310311 etc.This 2Tr/1C driving circuit comprises write transistor TR _wwith driving transistors TR _dsuch two transistors and a capacitor C ₁, as shown in Figure 3.

By following, the operation comprising this organic EL display element of this 2Tr/1C driving circuit is described tout court.As shown in the timing diagram of Figure 22, in period TP (2) ₃with period TP (2) ₅in carry out starting voltage Processing for removing.Then, in period TP (2) ₇in carry out writing process, and in period TP (2) ₈in flow from driving transistors TR in luminous component ELP _ddrain region flow to the drain current Ids of source area.Substantially, this organic EL display element is with the Intensity LEDs corresponding with the product of the value of this drain current Ids flowed in this luminous component ELP of the luminescence efficiency with this luminous component ELP.

The operation of the organic EL display element comprising this 2Tr/1C driving circuit is described in detail later with reference to Figure 22 and Figure 24 A to Figure 29.

Usually, in a display device, brightness is along with running time elongated and step-down.In the display device utilizing organic EL display element, observe the brightness that the rheological parameters' change with time due to the luminescence efficiency of luminous component causes and decline.Therefore, in a display device, when long-time display single pattern, what is called burn (burn-in) phenomenon etc. of the brightness change caused due to display pattern may be observed.Such as, as shown in fig. 32 a, make this display device for a long time in the upper right portion of the viewing area EA of organic EL display (with white) show character and with the state in all regions of black display except character under operate.After this, as viewing area EA whole with white displays, the brightness showing the upper right portion of character in the EA of viewing area reduces (as shown in fig. 32b) relatively, and it is identified as unnecessary pattern.Like this, when phenomenon of burning occurs, the display quality of display device reduces.

Summary of the invention

Can to drive with box lunch and compensate the brightness that causes due to burn during the display element that burn occurs and decline by controlling display element, the display quality solving the display device caused due to burn phenomenon declines.But such as in the luminous component of organic EL display element, the decline of luminescence efficiency depends on the display brightness of image and the history of running time.In the method that the brightness caused due to burn phenomenon in the rheological parameters' change with time data compensating with reference to the table storing the rheological parameters' change with time data measured of repetitive measurement operation history in advance declines, the scale that there is control circuit increases and controls the problem that complicates.

Therefore, desirable to provide storing the display history of brightness of image and the history of running time as data separately by reflecting these history to compensate the display device that the brightness caused due to burn phenomenon declines, or provide can by reflecting these history to compensate the display-apparatus driving method that the brightness caused due to burn phenomenon declines.

Embodiment of the present disclosure relates to display device, and it comprises: display board, and this display board comprises the display element with current drive-type luminous component and this display board shows image based on vision signal; and brightness correction unit, it is by correcting the gray-scale value of input signal and exporting calibrated input signal as vision signal, the brightness of described display element is corrected when working as display board display image, wherein this brightness correction unit comprises: running time conversion factor retainer, its store as running time conversion factor until the rheological parameters' change with time of brightness reach the running time of the determined value that each display element is operated based on the vision signal of various gray-scale value value and until the rheological parameters' change with time of brightness reaches the ratio of the value of the running time of this determined value making each display element operate based on the vision signal of predetermined benchmark gray-scale value, reference operating time counter, it carrys out the value of Calculation Basis running time by the value value of the running time conversion factor corresponding with the gray-scale value of vision signal being multiplied by the unit interval, in this reference operating time, when the display element of correspondence to equal the rheological parameters' change with time of the brightness of each display element when display element corresponding to hypothesis operates based on the vision signal of this predetermined benchmark gray-scale value based on the rheological parameters' change with time of brightness of each display element during vision signal operation scheduled unit time, accumulation reference operating time reservoir, its accumulation reference operating time storing the value by accumulating the reference operating time calculated by reference operating time counter about each display element and obtain, datum curve reservoir, it stores the datum curve of the relation represented between the running time of each display element and the rheological parameters' change with time of the brightness of the display element corresponding when corresponding display element operates based on the vision signal of predetermined benchmark gray-scale value, gradation correction value holder, it calculates the grey scale correction values of the rheological parameters' change with time of the brightness for compensating each display element with reference to accumulation reference operating time reservoir and datum curve reservoir, and store the grey scale correction values corresponding with each display element, and video signal generator, it corrects the gray-scale value of the input signal corresponding with each display element based on the grey scale correction values be stored in gradation correction value holder, and export calibrated input signal as vision signal, wherein this display board comprises mute (dummy) display element not making image display, and this running time conversion factor retainer comprises running time conversion factor renewal part, for by the value of datum curve is compared to come renewal rewards theory time conversion factor with the rheological parameters' change with time of the running time when this dummy argument part operates based on the vision signal of predetermined gray-scale value and brightness.

According in the display device of embodiment of the present disclosure, the history of brightness of display image and the history of running time can be stored as data and by reflecting these history to compensate that the brightness caused due to burn phenomenon declines by independent.Because running time conversion factor retainer is by comparing to come renewal rewards theory time conversion factor, so the characteristic unevenness that can depend on display board controls by the value of datum curve with the rheological parameters' change with time of the running time when this dummy argument part operates based on the vision signal of predetermined gray-scale value and brightness.

Accompanying drawing explanation

Fig. 1 is the concept map of diagram according to the display device of example 1;

Fig. 2 is the block diagram of the configuration of schematically diagram brightness correction unit;

Fig. 3 is the equivalent circuit diagram of the display element of composition display board;

Fig. 4 A is the fragmentary sectional view that schematically diagram comprises a part of the display element of display board;

Fig. 4 B is the fragmentary sectional view that schematically diagram comprises a part of the mute display element in display board;

Fig. 5 A is the curve map of the relation between the value of video voltage under diagram original state in display element and the brightness value of display element;

Fig. 5 B is the curve map of the relation between the value of the video voltage be illustrated in the display element that rheological parameters' change with time occurs and the brightness value of display element;

Fig. 6 is the curve map of the relation between the relative brightness of the cumulative operational time be schematically illustrated in when the vision signal making display element based on various gray-scale value operates and the display element caused due to rheological parameters' change with time changes;

Fig. 7 is the curve map of the relation between the relative brightness of the running time be schematically illustrated in when making display element operate while the gray-scale value changing vision signal and the display element caused due to rheological parameters' change with time changes;

Fig. 8 is that schematically diagram is by the reference number C L in Fig. 7 ₁, CL ₂, CL ₃, CL ₄, CL ₅and CL ₆the sketch of the corresponding relation between indicated graph parts and the curve shown in Fig. 6;

Fig. 9 is schematic illustrations until the relative brightness change of the display element caused due to rheological parameters' change with time reaches the curve map of the relation between the cumulative operational time of the determined value " β " making display element operate based on vision signal and the gray-scale value of this vision signal;

Figure 10 is the curve map that the running time of working as when display element is operated based on the operation history shown in Fig. 7 is converted to when the method supposing reference operating time when making display element operate based on the vision signal of predetermined gray-scale value by schematically diagram;

Figure 11 is the curve map of the relation be illustrated between the gray-scale value of vision signal and running time conversion factor;

Figure 12 is the block diagram of the configuration of brightness correction unit in schematic illustrations benchmark example;

Figure 13 is the curve map that schematic illustrations is stored in the data in datum curve reservoir;

Figure 14 is the curve map that schematically diagram is stored in the data in running time conversion factor retainer;

Figure 15 is the curve map that schematically diagram is stored in the data in accumulation reference operating time reservoir;

Figure 16 is the curve map of the operation of the grey scale correction values counter of schematically diagram gradation correction value holder;

Figure 17 is the curve map of the operation of the grey scale correction values reservoir of schematically diagram gradation correction value holder;

Figure 18 is the curve map of the method that the value of datum curve compares with the value of measured mute display element by schematically diagram;

Figure 19 is the curve map that schematically diagram is stored in the more new data in running time conversion factor retainer;

Figure 20 is the curve map of the method that the value of datum curve compares with the value of measured mute display element by schematically diagram;

Figure 21 is the curve map that schematically diagram is stored in the more new data in running time conversion factor retainer;

Figure 22 is the timing diagram of the operation being schematically illustrated in display element in the display-apparatus driving method according to example 1 or example 2;

Figure 23 is the timing diagram of the operation being schematically illustrated in mute display element in the display-apparatus driving method according to example 1 or example 2;

Figure 24 A and Figure 24 B is the sketch of the ON/OFF state of the transistor be schematically illustrated in the driving circuit of display element;

Figure 25 A and Figure 25 B is the sketch of the ON/OFF state of the transistor be schematically illustrated in the driving circuit of the display element being routed to Figure 24 B;

Figure 26 A and Figure 26 B is the sketch of the ON/OFF state of the transistor be schematically illustrated in the driving circuit of the display element being routed to Figure 25 B;

Figure 27 A and Figure 27 B is the sketch of the ON/OFF state of the transistor be schematically illustrated in the driving circuit of the display element being routed to Figure 26 B;

Figure 28 A and Figure 28 B is the sketch of the ON/OFF state of the transistor be schematically illustrated in the driving circuit of the display element being routed to Figure 27 B;

Figure 29 is the sketch of the ON/OFF state of the transistor be schematically illustrated in the driving circuit of the display element being routed to Figure 28 B;

Figure 30 is the equivalent circuit diagram of the display element comprising driving circuit;

Figure 31 is the equivalent circuit diagram of the display element comprising driving circuit; With

Figure 32 A and Figure 32 B is the front schematic view of the viewing area of diagram burn phenomenon in a display device.

Embodiment

Hereafter, example of the present disclosure will be described with reference to the drawings.The disclosure is not limited to these examples, and various numerical value in this specific embodiment and material are all only examples.In the following description, by ingredient identical for the Reference numeral index with identical or the ingredient with identical function, and its description will not be repeated.This description will be made with following order.

1. the general description of display device and display-apparatus driving method

2. example 1

3. example 2 (other)

[general description of display device and display-apparatus driving method]

From numerically controlled viewpoint, the value of preferred input signal and vision signal with 2 level (step) change shown of power table.According in the display device of embodiment of the present disclosure and display-apparatus driving method, the gray-scale value of vision signal can be greater than the maximal value of the gray-scale value of input signal.

Such as, input signal can stand 8 gray-scale Control, and vision signal can stand the gray-scale Control being greater than 8.Such as, can consider that wherein vision signal stands 9 configurations controlled, but the disclosure is not limited to this example.

According in the display device of embodiment of the present disclosure, along with the unit interval shortens, the degree of accuracy that burn compensates becomes to be improved more, but the processing load of luminance correction device also becomes large.The technical manual that unit interval can depend on display device is suitably arranged.

Such as, be given as the time of the inverse of frame rate of display, that is, the so-called time shared by the frame period, can the unit interval be set to.As an alternative, the time shared by period comprising the frame period of predetermined quantity can be set to the unit interval.In the later case, in the unit interval, the vision signal of various gray-scale value is supplied to a display element.In this case, such as, it only must be configured to only with reference to the gray-scale value in the first frame period of this unit interval.

According in the display device of embodiment of the present disclosure, running time conversion factor renewal part can be configured to every renewal rewards theory scheduled operating time time conversion factor.

Such as, as long as display device can be configured to operate one hour with regard to renewal rewards theory time conversion factor, as long as or display device can be configured to operates 10 hours with regard to renewal rewards theory time conversion factor.Usually, the unit interval becomes shorter, and the precision that burn compensates just is raised higher, but the processing load of brightness correction unit also becomes heavier.The specification suitably setting unit time of display device can be depended on.

According in the display device of embodiment of the present disclosure, running time conversion factor renewal part can by relatively carrying out renewal rewards theory time conversion factor by the value of datum curve from the running time of multiple mute display element operated based on different gray-scale value and the rheological parameters' change with time of brightness.

Particularly, such as, can be configured to by interpolation, by the data that the value of datum curve and multiple running time of mute display element and the rheological parameters' change with time of brightness are compared and obtained, carry out the value of renewal rewards theory time conversion factor.

According in the display device of embodiment of the present disclosure, running time conversion factor renewal part can by comparing to come renewal rewards theory time conversion factor by the value of datum curve with the running time of mute display element operated based on single gray-scale value and the rheological parameters' change with time of brightness.

Particularly, can be configured to the running time conversion factor of original state is multiplied by the obtained factor by the running time conversion factor of storing initial state in running time conversion factor retainer, based on the data acquisition pre-determined factor by the value of datum curve and the running time of mute display element operated based on single gray-scale value and the rheological parameters' change with time of brightness are compared and obtained, carry out the value of renewal rewards theory time conversion factor.

Mute display element is preferably arranged in the part around viewing area.Can by process from being arranged in the face of the monochrome information of optical sensor of mute display element obtains the rheological parameters' change with time of mute display element.

The well-known sensor of such as photodiode or phototransistor and so on can be used as optical sensor.Such as, the optical sensor arrangement as the component independent of display board can be become correspond to mute display element.As an alternative, such as, the semiconductor element with the same-type of the semiconductor element such as forming display element (such as, composition drives the transistor of the driving circuit of luminous component) can be used, optical sensor is inserted display board.

In the display device with above-mentioned preferred disposition, form the reference operating time counter of this brightness correction unit, accumulation reference operating time reservoir, datum curve reservoir, gradation correction value holder, video signal generator and running time conversion factor renewal part with well-known circuit component.The various circuit (such as power circuit, sweep circuit and signal output apparatus) described below are also like this.

Have above-mentioned various configuration, the configuration of so-called monochrome display or color monitor configuration can be had according to the display device of embodiment of the present disclosure.

When colour display configuration, a pixel can comprise multiple sub-pixel, and such as, a pixel can comprise such three sub-pixels of red emission sub-pixel, green emission sub-pixel and blue emission sub-pixel.Can form the sub-pixel also comprising one or more type except the sub-pixel of this three types group (such as additionally comprise the group of the sub-pixel improving brightness that emits white light, additionally comprise send out complementary color light to extend the sub-pixel of range of color reproduction group, additionally comprise Yellow light-emitting low temperature to extend the sub-pixel of range of color reproduction group and additionally comprise jaundice look and cyan to extend the group of the sub-pixel of range of color reproduction).

The example of the pixel value in this display device comprises several image display resolution, such as VGA (640,480), SVGA (800,600), XGA (1024,768), APRC (1152,900), SXGA (1280,1024), UXGA (1600,1200), HDTV (1920,1080) and QXGA (2048,1536), (1920,1035), (720,480) and (1280,960), but pixel value is not limited to these values.

According in the display device of embodiment of the present disclosure, the example of the current drive-type luminous component of composition display element includes organic electro luminescent part, LED luminous component and semiconductor laser luminous component.These luminous components can use well-known material or method to be formed.From the view point of the structure of panel display apparatus, luminous component is preferably formed by organic electroluminescent part.This organic electroluminescent part can be top emission type or bottom emission type.Organic electroluminescent part can comprise anode, hole transmission layer, luminescent layer, electron transfer layer and negative electrode.

The display element of this display board is formed on (such as, on base) in certain plane, and each luminous component is formed on the driving circuit of the luminous component driving correspondence, such as, has interlayer insulative layer sandwiched therebetween.

Composition drives the example of the transistor of the driving circuit of luminous component to be n-channel thin film transistor (TFT).The transistor forming this driving circuit can be enhancement mode or prevent type (depressiontype).N-channel transistor can have LDD (lightly doped drain) structure formed there.In some cases, LDD structure may be asymmetrical.Such as due to when the display element luminescence of correspondence big current flow in driving transistors, so can when luminescence be used as drain region an only regions and source/drain in form this LDD structure.Such as, p channel thin-film transistor can be used.

The dielectric layer that the capacitor forming driving circuit can comprise an electrode, another electrode and insert between each electrode.The transistor and the capacitor that form this driving circuit are formed on certain plane (such as, base) on, and luminous component is formed on the composition transistor of driving circuit and capacitor (such as, when inserting interlayer insulative layer betwixt).Another regions and source/drain of driving transistors is such as connected to one end (anode electrode of such as this luminous component) of this luminous component via contact hole.This transistor can be formed in the semiconductor substrate.

The example of the base that will describe below or the material of substrate is except glass material (such as high strain-point glass, soda-lime glass (Na ₂oCaOSiO ₂), Pyrex (Na ₂oB ₂o ₃siO ₂), forsterite (2MgOSiO ₂) and solder glass (Na ₂oPbOSiO ₂)) outside, also comprise and there is flexible polymeric material, such as Poly-s 179 (PES), polyimide, polycarbonate (PC) and polyethylene terephthalate (PET).Various coating can be carried out in the surface of base or substrate.The material of base and substrate can be same to each other or different to each other.When use by have flexible polymeric material form base and substrate time, can flexible display apparatus be formed.

In the display device, such as the various wires of sweep trace, data line and power lead and so on can have well-known configuration or structure.

In two regions and source/drain of a transistor, term " regions and source/drain " can be used to refer to the regions and source/drain being connected to power supply.If transistor is in ON state, then it refers to form raceway groove between each regions and source/drain.Do not consider whether electric current flow to another regions and source/drain from a regions and source/drain of this transistor.On the other hand, if transistor is in OFF state, then it refers between each regions and source/drain, not form raceway groove.Regions and source/drain can be formed by the conductive material of the polysilicon or amorphous silicon and so on that such as comprise impurity, or regions and source/drain can be formed by metal, alloy, conducting particles, its stacked structure or the layer comprising organic material (conducting polymer).

When the various expression formulas in this instructions substantially effectively and when described expression formula mathematically strictly effectively time, the condition in described expression formula is satisfied.About the validity of described expression formula, the various unevenness caused when designing or manufacture display element or display device are permissible.

For in timing diagram described below, represent that the length (time span) of the transverse axis of various period is signal, and the ratio of the time span of period is not shown.This point is also right on the vertical axis.Waveform in timing diagram is also signal.

[example 1]

Example 1 relates to display device according to embodiment of the present disclosure and display-apparatus driving method.

Fig. 1 is the conceptual diagram of diagram according to the display device of example 1.Display device according to example 1 comprises: display board 20, wherein arrange each there is current drive-type luminous component display element 10 and based on vision signal VD _sigdisplay image; And luminance correction device 110, it is by correcting input signal VD _siggray-scale value and export calibrated input signal as vision signal VD _sig, correct the brightness of the display element when showing image on the display panel 20.In example 1, luminous component is made up of organic electroluminescent part.

The region (viewing area) that display board 20 shows image is included in the first direction (X-direction in Fig. 1, it is also referred to as line direction) on N number of display element and the second direction (Y-direction in Fig. 1, it is also referred to as column direction) on total NxM display element 10 of M display element, it is arranged in two-dimensional matrix.The line number of the display element 10 in viewing area is M, and the quantity of display element 10 in every a line is N.Figure 1 illustrates 3 × 4 display elements 10, it is only an example.

Display board 20 comprises: many (M) bar sweep trace SCL, and it is connected to sweep circuit 101 and extends in a first direction; Many (N) bar data line DTL, it is connected to the main signal output circuit 102A of signal output apparatus 102 and extends in a second direction; And many (M) bar power lead PS1, it is connected to power supply unit 100 and extends in a first direction.Display element 10 during m is capable is connected to m article of sweep trace SCL _mwith m article of power lead PS1 _mand form row of display elements, wherein m=1,2 ..., M.Display element 10 in n-th row is connected to n-th data line DTL _n, wherein n=1,2 ..., N.

Display board 20 comprises the mute display element 10 not making image display _dmywith the dummy data line DTL that the mute signal output apparatus 102A being connected to signal output apparatus 102 also extends in a second direction _dmy.Mute display element 10 _dmyexcept not making image display, there is the configuration identical with display element 10.

Such as, P (wherein P is natural number) individual mute display element 10 _dmyarrange in a second direction with the predetermined gap that the display element 10 in arranging with unshowned N separates.Mute display element 10 _dmybe arranged in the inactive area around viewing area.Mute display element 10 _dmyarrangement be not limited to this example, but the design of display device can be depended on or specification is suitably arranged.

Dummy data line DTL _dmybe connected to all mute display elements 10 _dmy.P (wherein p=1,2 ..., P) row in mute display element 10 _dmybe connected to p sweep trace SCL and p power lead PS1.

Therefore, by utilizing the first sweep trace SCL to scan display element 10 in the first row and mute display element 10 _dmy, and by utilizing the second sweep trace SCL to scan display element 10 in the second row and mute display element 10 _dmy.This point is for the display element 10 in other row and mute display element 10 _dmyalso be right.

Display device 1 comprises such as with the optical sensor 120 that phototransistor is formed.As shown in Figure 4 B, optical sensor 120 is arranged on the display panel 20 so that in the face of mute display element 10 _dmy.The monochrome information of optical sensor 120 is sent to brightness correction unit 110.

Power supply unit 100 and sweep circuit 101 can have well-known configuration or structure.

Signal output apparatus 102 comprises unshowned D/A converter or latch cicuit.The main signal output circuit 102A of signal output apparatus 102 is based on vision signal VD _siggray-scale value generating video signal voltage V _sig, keep the video voltage V corresponding with a line _sig, and by video voltage V _sigbe fed to N bar data line DTL.Signal output apparatus 102 comprises unshowned selector circuit and comes wherein by video voltage V by the switching of selector circuit _sigthe state being fed to data line DTL with wherein by reference voltage V _ofsswitch between the state being fed to data line DTL.

On the other hand, the mute signal output apparatus 102B of signal output apparatus 102 is such as based on vision signal (mute vision signal) VD of the predetermined gray-scale value wherein generated _dmygenerating video signal voltage (mute video voltage) V _dmyand this video voltage is fed to dummy data line DTL _dmy.Vision signal VD _dmybe and mute display element 10 _dmythe signal of corresponding predetermined gray-scale value, and be regardless of input signal vD _sigand generate.This signal output apparatus comes wherein by video voltage V by the switching of selector circuit _dmybe fed to dummy data line DTL _dmystate with wherein by reference voltage V _ofsbe fed to dummy data line DTL _dmystate between switch.

Power supply unit 100, sweep circuit 101 and signal output apparatus 102 can use the formations such as well-known circuit component.

Be monochromatic display device according to the display device 1 of example 1, it comprises multiple display element 10 (such as, N × M=640 × 480).Each display element 10 forms a pixel.In viewing area, described pixel is arranged on line direction and column direction with two-dimensional matrix.

Be used for the sweep signal of self-scanning circuit 101 by line sequentially scanning display apparatus 1.Be positioned at display element 10 on the n-th capable position of m hereinafter referred to as (n, m) display element 10 or (n, m) pixel.The input signal vD corresponding with (n, m) display element 10 _siguse vD _{sig (n, m)}represent, and with (n, m) display element 10 corresponding, the video voltage V that corrected by brightness correction unit 110 _siguse V _{dSig (n, m)}represent.Based on vision signal VD _{sig (n, m)}video voltage V _{sig (n, m)}represent, and based on vision signal VD _dmyvideo voltage V _dmyrepresent.

As mentioned above, brightness correction unit 110 corrects input signal vD _siggray-scale value and export calibrated input signal as vision signal VD _sig.

The object illustrated for convenience, supposes input signal vD _siggray scale figure place be 8.Depend on the brightness of the image that will show, input signal vD _siggray-scale value be one of 0 to 255.Here, suppose that the brightness of the image that will show becomes large along with gray-scale value and uprises.

Suppose vision signal VD _siggray scale figure place be 9.Depend on rheological parameters' change with time and the input signal vD of display element 10 _siggray-scale value, vision signal VD _siggray-scale value be one of 0 to 511.Display element 10 (that is, the display element 10 of the brightness change caused due to rheological parameters' change with time does not occur) under original state is supplied with and input signal vD from brightness correction unit 110 _sigthe vision signal VD of the identical gray-scale value of gray-scale value _sig.

Be similar to vision signal VD _sig, suppose vision signal VD _dmygray scale figure place be 9.As mentioned above, the scanning of the display element 10 in also capable with first to P scan first to P capable in mute display element 10 _dmy.The object illustrated for convenience, in example 1, supposes P=5, the mute display element 10 in the first row _dmybased on the vision signal VD of gray-scale value 100 _dmyoperation, and the mute display element 10 in the second row _dmybased on the vision signal VD of gray-scale value 200 _dmyoperation.Mute display element 10 in the third line _dmybased on the vision signal VD of gray-scale value 300 _dmyoperation, the mute display element 10 in fourth line _dmybased on the vision signal VD of gray-scale value 400 _dmyoperation, and the mute display element 10 in fifth line _dmybased on the vision signal VD of gray-scale value 500 _dmyoperation.

Fig. 2 is the block diagram of the configuration of schematically diagram brightness correction unit.The operation of brightness correction unit 110 is described in detail later with reference to Figure 12 ~ Figure 19.Below brightness correction unit 110 will schematically be described.

Brightness correction unit 110 comprises running time conversion factor retainer 113, reference operating time counter 112, accumulation reference operating time reservoir 114, datum curve reservoir 116, gradation correction value holder 115 and video signal generator 111.These parts are made up of counting circuit or memory device (storer), and can be made up of well-known circuit component.

Running time conversion factor retainer 113, as running time conversion factor, stores until the rheological parameters' change with time of brightness reaches the vision signal VD making each display element 10 based on various gray-scale value _sigthe value of the running time till the determined value of operation and until make corresponding display element 10 based on the vision signal VD of predetermined benchmark gray-scale value _sigthe ratio of the value of the running time till the rheological parameters' change with time of brightness during operation.

Running time conversion factor retainer 113 comprises running time conversion factor reservoir 113A and running time conversion factor upgrades part 113B.Running time conversion factor upgrades part 113B and passes through the value of the datum curve that will be stored in datum curve reservoir 116 and work as mute display element 10 _dmybased on the vision signal VD of constant greyscale value _dmyrunning time during operation and the rheological parameters' change with time of brightness compare, and update stored in the running time conversion factor in running time conversion factor reservoir 113A.Particularly, running time conversion factor reservoir 113A stores the multiple function f be updated successively as table _{cSC_APT}, they indicate the relation of the curve map of Figure 19.Running time conversion factor upgrades part 113B and is made up of counting circuit etc., and running time conversion factor reservoir 113A is made up of the memory device of such as rewritable non-volatile storer and so on.

Reference operating time counter 112 by will with vision signal VD _sigthe value of running time conversion factor corresponding to gray-scale value be multiplied by the value of unit interval, carry out the value of Calculation Basis running time, in this reference operating time, when the display element 10 of correspondence is based on vision signal VD _sigduring operation scheduled unit time, the rheological parameters' change with time of the brightness of each display element 10 equals when supposing the vision signal VD of corresponding display element 10 based on predetermined benchmark gray-scale value _sigthe rheological parameters' change with time of the brightness of display element 10 corresponding during operation.To describe below " scheduled unit time " and " predetermined benchmark gray-scale value ".

The accumulation reference operating time that accumulation reference operating time reservoir 114 stores the value by accumulating the reference operating time calculated by reference operating time counter about each display element 10 and obtains.Accumulation reference operating time is the value of the operation history of reflection display device 1, and not by disconnecting reset such as display device 1 grade.Accumulation reference operating time reservoir 114 is made up of the rewritable non-volatile memory device comprising the storage area corresponding with display element 10, and stores the data shown in Figure 15.Accumulation reference operating time reservoir 114 comprises the storage area represented by the Reference numeral AP in Figure 15, to store mute display element 10 _dmythe accumulated value of value of running time.

The running time that datum curve reservoir 116 storage list is shown in each display element 10 with when corresponding display element 10 is based on the vision signal VD of predetermined benchmark gray-scale value _sigthe datum curve of the relation between the rheological parameters' change with time of the brightness of display element 10 corresponding during operation.Particularly, datum curve reservoir 116 is in advance as the function f of the datum curve shown in table storage list diagram 13 _rEF.

Utilize the display device with same specification in advance, based on measured data etc., determine function f _rEF.

In example 1, " scheduled unit time " is defined as the time that a so-called frame period takies, and " predetermined benchmark gray-scale value " is arranged to 200, but the disclosure is not limited to these settings.These settings are suitably selected in the design that can depend on display device.

Gradation correction value holder 115 calculates the corrected value of the gray-scale value of the rheological parameters' change with time of the brightness for compensating each display element 10 with reference to accumulation reference operating time reservoir 114 and datum curve reservoir 116, and stores the grey scale correction values corresponding with each display element 10.Gradation correction value holder 115 comprises grey scale correction values counter 115A and grey scale correction values reservoir 115B.Grey scale correction values counter 115A is made up of counting circuit.Grey scale correction values reservoir 115B comprises the storage area corresponding with display element 10, is made up of recordable memory part, and stores the data shown in Figure 17.

Video signal generator 111 corrects the input signal vD corresponding with each display element 10 based on the corrected value of the gray-scale value kept by gradation correction value holder 115 _siggray-scale value, and export calibrated input signal as vision signal VD _sig.

So far, brightness correction unit 110 has been schematically illustrated.The configuration of display device 1 will be described below.

Fig. 3 is the equivalent circuit diagram of the display element of composition display board.

Each display element 10 comprises current drive-type luminous component ELP and driving circuit 11.Driving circuit 11 at least comprises the driving transistors TR with grid and regions and source/drain _dwith capacitor C ₁.Electric current is via driving transistors TR _dregions and source/drain flow in luminous component ELP.Although describe in detail later with reference to Fig. 4 A, display element 10 has stacking driving circuit 11 wherein and is connected to the structure of luminous component ELP of driving circuit 11.Due to mute display element 10 _dmythere is the configuration identical with display element 10, so only otherwise need especially, mute display element 10 will not be described _dmyconfiguration.

Except driving transistors TR _doutside, driving circuit 11 also comprises write transistor TR _w.Driving transistors TR _dwith write transistor TR _wall formed by n channel TFT.Such as, write transistor TR _wcan be formed by p channel TFT.Driving circuit 11 can also comprise other transistors, such as, as shown in figures 30 and 31.

Capacitor C ₁be used to keep grid about driving transistors TR _dthe voltage (so-called grid-source voltage) of source region.In this case, " source region " refers to the regions and source/drain being used as " source region " when luminous component ELP is luminous.When display element 10 is in luminance, driving transistors TR _da regions and source/drain (being connected to the region of the power lead PS1 in Fig. 3) as drain region, and another regions and source/drain (being connected to the region of one end of luminous component ELP, that is, anode electrode) is as source region.Capacitor C ₁an electrode and another electrode be connected respectively to driving transistors TR _danother regions and source/drain and grid.

Write transistor TR _wcomprise the grid being connected to sweep trace SCL, the regions and source/drain being connected to data line DTL and be connected to driving transistors TR _danother regions and source/drain of grid.

Driving transistors TR _dgrid form write transistor TR wherein _wanother regions and source/drain be connected to capacitor C ₁the first node ND of another electrode ₁.Driving transistors TR _danother regions and source/drain form capacitor C wherein ₁an Electrode connection to the Section Point ND of the anode electrode of luminous component ELP ₂.

The other end (particularly, cathode electrode) of luminous component ELP is connected to second source line PS2.As shown in fig. 1, second source line PS2 is to all display elements 10 and all mute display elements 10 _dmyshare.

By predetermined voltage V _catthe cathode electrode of luminous component ELP is fed to from second source line PS2.The electric capacity reference number C of luminous component ELP _eLrepresent.The starting voltage V that luminous component ELP luminescence needs _th-ELrepresent.That is, when applying to equal between the anode electrode and cathode electrode of luminous component ELP or higher than V _th-ELvoltage time, luminous component ELP is luminous.

Such as, luminous component ELP has well-known configuration or structure, comprises anode electrode, hole transmission layer, luminescent layer, electron transfer layer and cathode electrode.

Driving transistors TR shown in Fig. 3 _dvoltage is configured to operate in zone of saturation when display element 10 is in luminance, and is actuated to the drain current I with expression formula 1 expression _dsflowing.As mentioned above, when display element 10 is in luminance, driving transistors TR _da regions and source/drain be used as drain region, and its another regions and source/drain be used as source region.The object illustrated for convenience, driving transistors TR _da regions and source/drain can referred to as drain region, and another regions and source/drain can referred to as source region.Reference numeral is defined as foloows.

μ: effective mobility

L: channel length

W: channel width

V _gs: grid is relative to the voltage of source region

V _th: starting voltage

C _ox: (certain dielectric constant of gate insulator) × (specific inductive capacity of vacuum)/(thickness of gate insulator)

k≡(1/2)·(W/L)·C _ox

I _ds＝k·μ·(V _gs-V _th) ²...(1)

By making drain current I _dsflow in luminous component ELP, the luminous component ELP of display element 10 is luminous.Depend on drain current I _dsvalue control the luminous intensity of luminous component ELP of display element 10.

With from being connected to write transistor TR _wthe sweep signal (that is, from the sweep signal of sweep circuit 101) of sweep trace SCL of grid control write transistor TR _woN/OFF state.

Based on the operation of the main signal output circuit 102A of signal output apparatus 102, various signal or voltage are applied to write transistor TR from data line DTL _wa regions and source/drain.Particularly, by video voltage V _sigwith predetermined reference voltage V _ofsthis is applied to from signal output apparatus 102.Except video voltage V _sigand reference voltage V _ofsoutside, other voltage can also be applied to this.

Based on the operation of the mute signal output apparatus 102B of signal output apparatus 102, by various signal or voltage from dummy data line DTL _dmybe applied to mute display element 10 _dmyin write transistor TR _wa regions and source/drain.Particularly, by video voltage V _dmywith predetermined reference voltage V _ofsthis is applied to from mute signal output apparatus 102B.

Be used for the sweep signal of self-scanning circuit 101 by line sequentially scanning display apparatus 1.In each horizontal scanning period, first by reference voltage V _ofsbe fed to data line DTL, and by video voltage V _sigbe fed to this.

Be similar to dummy data line DTL _dmy, in each horizontal scanning period, reference voltage V _ofsfirst data line DTL is supplied to, and by video voltage V _dmybe fed to this.In example 1, in the 6th or its subsequent rows, there is not mute display element 10 _dmy.The object illustrated for convenience, when scanning the 6th or its subsequent rows will in fact with reference voltage V _ofsidentical voltage is as video voltage V _dmyapply.

Fig. 4 A is the fragmentary sectional view that schematic illustrations comprises the part of the display element in display board.By the transistor TR of driving circuit 11 _dand TR _wand capacitor C ₁be formed on pedestal 21, and luminous component ELP is formed in the transistor TR of driving circuit 11 _dand TR _wand capacitor C ₁on, such as, there is insertion interlayer insulative layer 40 therebetween.Driving transistors TR _danother regions and source/drain be connected to the anode electrode of luminous component ELP via contact hole.In Figure 4 A, illustrate only driving transistors TR _d.Other transistors not shown.

Fig. 4 B is the fragmentary sectional view that schematic illustrations comprises the part of the display element in display board.Except in the inactive area that mute display element is arranged in around viewing area, mute display element 10 _dmyconfiguration identical with display element 10.Such as, in the transparent substrates 22 that will describe after the optical sensor 120 be made up of phototransistor is arranged on, so that in the face of mute display element 10 _dmy.

The configuration of display element 10 is described in detail below with reference to Fig. 4 A.Driving transistors TR _dcomprise grid 31, gate insulator 32, be formed in regions and source/drain 35 and 35 in semiconductor layer 33 and the channel formation region 34 corresponding with a part for the semiconductor layer 33 between regions and source/drain 35 and 35.On the other hand, capacitor C ₁comprise another electrode 36, by the dielectric layer extended to form of gate insulator 32 and an electrode 37.A part for grid 31, gate insulator 32 and capacitor C ₁another electrode 36 be formed on pedestal 21.Driving transistors TR _da regions and source/drain 35 be connected to wire 38 (corresponding to power lead PS1), and another regions and source/drain 35 is connected to an electrode 37.Driving transistors TR _dwith capacitor C ₁be capped interlayer insulative layer 40, and on interlayer insulative layer 40, form the luminous component ELP comprising anode electrode 51, hole transmission layer, luminescent layer, electron transfer layer and cathode electrode 53.In the figure, hole transmission layer, luminescent layer and electron transfer layer are shown as simple layer 52.Second interlayer insulative layer 54 is formed on not to be provided on the interlayer insulative layer 40 of luminous component ELP, and the second interlayer insulative layer 54 and cathode electrode 53 arrange transparent substrates 22, and outputs to outside from the light that luminescent layer is launched via substrate 22.An electrode 37 and anode electrode 51 are interconnected via the contact hole be formed in interlayer insulative layer 40.Cathode electrode 53 is connected to the wire 39 (corresponding to second source line PS2) in the extension being formed in gate insulator 32 via the contact hole 56 and 55 be formed on the second interlayer insulative layer 54 and interlayer insulative layer 40.

To the method manufacturing and comprise the display device 1 of display board 20 be described below.First, utilize well-known method on pedestal 21, suitably form various wires, the composition capacitor C of such as sweep trace SCL and so on ₁electrode, the transistor formed by semiconductor layer, interlayer insulative layer and contact hole etc.By utilizing well-known method to carry out film forming (filmforming) and molding (patterning) process, formed with the luminous component ELP of matrix arrangement.The periphery of the pedestal 21 and substrate 22 that experienced by above-mentioned process is sealed, and is such as attached on substrate 22 by optical sensor 120 with bonding agent, so that in the face of mute display element 10 _dmy.After this, it is connected internally to external circuit, thus obtains display device 1.

To the method (hereafter, being also abbreviated as the driving method according to example 1 simply) driven according to the display device 1 of example 1 be described below.The display frame speed of display device 1 is configured to FR (/ second).Drive simultaneously composition be arranged in m capable in the display element 10 of N number of pixel.In other words, arranging in N number of display element 10 in a first direction, the behavior unit belonged to display element controls its luminous/non-luminous time.When by row with the scanning period of often going during line order scanning display apparatus 1, that is, a horizontal scanning period (so-called 1H), is less than (1/FR) × (1/M) second.

In subsequent descriptions, voltage or potential value as follows.But these values are only examples, and voltage or current potential are not limited to these values.

V _sig: video voltage, 0 volt (gray-scale value 0) is to 10 volts (gray-scale values 511)

V _dmy: video voltage, has the value corresponding with the vision signal of gray-scale value 100,200,300,400 and 500

V _ofs: driving transistors TR is applied to _dgrid (first node ND ₁) reference voltage, 0 volt

V _cC-H: make the driving voltage that electric current flows in luminous component ELP, 20 volts

V _cC-L: for initialization driving transistors TR _danother regions and source/drain (Section Point ND ₂) the initialization voltage of current potential ,-10 volts

V _th: driving transistors TR _dstarting voltage, 3 volts

V _cat: the voltage being applied to the cathode electrode of luminous component ELP, 0 volt

V _th-EL: the starting voltage of luminous component ELP, 4 volts

The operation of (n, m) display element 10 is described in detail later with reference to Figure 22 to Figure 29.First, the principle of rheological parameters' change with time of brightness and the method for the rheological parameters' change with time of compensate for brightness of display element 10 will be described.

As described in the background section, at period TP (2) as shown in Figure 22 ₃with period TP (2) ₅in carry out starting voltage Processing for removing.Then, in period TP (2) ₇in carry out writing process and in period TP (2) ₈in from driving transistors TR _ddrain region flow to the drain current I of source region _dsflow in luminous component ELP, thus luminous component ELP is luminous.The drain current I flowed in the luminous component ELP of (n, m) display element 10 can be expressed by expression formula 5 _ds.

I _ds＝k·μ·(V _{Sig_m}-V _Ofs-ΔV) ²...(5)

In expression formula 5, " V _{sig_m}" represent the video voltage V of (n, m) display element 10 _{sig (n, m)}, and " Δ V " represents Section Point ND ₂current potential increment Delta V (potential correction value).Potential correction value Δ V is described in detail later with reference to Figure 28 B.

The object illustrated for convenience, supposes that the value of " Δ V " is enough less than V _{sig_m}.As mentioned above, due to V _ofsit is 0 volt, so expression formula 5 can be modified as expression formula 5 '.

I _ds＝k·μ·V _{Sig_m} ²...(5’)

As can be found out from expression formula 5 ', drain current I _dswith video voltage V _{sig (n, m)}value square proportional.Display element 10 is with the luminescence efficiency and the drain current I flowed in luminous component ELP with luminous component ELP _dsintensity LEDs corresponding to the product of value.Therefore, video voltage V _sigvalue be substantially arranged to and vision signal VD _sigthe square root of gray-scale value proportional.

Fig. 5 A is the curve map of the relation between the value of the video voltage of diagram in an initial condition in display element and the brightness value of display element.

In fig. 5, transverse axis represents video voltage V _sigvalue.On this transverse axis, corresponding vision signal sVD _siggray-scale value be described within [].This point is also right to Fig. 5 B that will describe later.In the other drawings, the numeric representation gray-scale value within [] is described in.

When the coefficient that will depend on the luminescence efficiency under the original state of luminous component ELP together with coefficient " k " and " μ " and determine is defined as α _initime, can by brightness LU such as LU=(VD _sig-Δ D) × α _iniand so on expression formula express.Here, " Δ D " represents so-called black, and depends on the specification of display device 1 or design and determine.Work as VD _sigduring < Δ D, in this expression formula, the value of LU is negative (-), but LU is in this case considered to " 0 ".

The object illustrated for convenience, supposes that the value of Δ D is 0.In this case, expression formula LU=VD _sig× α _iniset up.Such as, as hypothesis α _ini=1.2 and based on the vision signal VD of gray-scale value 500 in a display device in an initial condition _sigduring display image, the brightness of this image is essentially 600cd/m ².In example 1, the maximum brightness value in the specification of display device 1 is 255 × α _ini.

Fig. 5 B is the curve map of the relation between the value of the video voltage be illustrated in the display element of rheological parameters' change with time generation and the brightness value of this display element.

Lower under the display element 10 brightness ratio original state that rheological parameters' change with time occurs.Particularly, as shown in Figure 5 B, the family curve after rheological parameters' change with time is slower than initial characteristic curve.Along with rheological parameters' change with time continues to occur, this family curve becomes slower.

When the coefficient luminescence efficiency after the rheological parameters' change with time depended in luminous component ELP determined together with coefficient " k " and " μ " is defined as α _tdctime, can by brightness LU such as LU=VD _sig× α _tdcand so on expression formula express.Here, α _tdc< α _inieffectively.In order to compensate the rheological parameters' change with time of the brightness of display element 10, display element 10 is only needed to pass through vision signal VD _siggray-scale value be multiplied by α _ini/ α _tdcoperate.

So far, the square ratio juris of the rheological parameters' change with time of the brightness compensating display element 10 has been described.The rheological parameters' change with time of the brightness of display element 10 depends on the brightness of image shown by display device 1 and the history of running time.The rheological parameters' change with time of the brightness of display element 10 depends on display element 10 to be changed.Therefore, in order to compensate the burn phenomenon of display device 1, need to control vision signal VD to each display element 10 _siggray-scale value.

The compensation of the burn phenomenon in display device 1 is schematically described with reference to Fig. 2.Reference operating time counter 112 by will with vision signal VD _siggray-scale value corresponding, value in running time conversion factor retainer 113 is multiplied by the value of unit interval, carrys out the value of Calculation Basis running time.The value that accumulation reference operating time reservoir 114 stores the value by accumulating the reference operating time value calculated by reference operating time counter 112 and obtains.Based on the data be stored in accumulation reference operating time reservoir 114, reference data curve reservoir 116 calculates the corrected value of the gray-scale value corresponding with each display element 10.Corrected value based on this gray-scale value corrects input signal vD _siggray-scale value, and using calibrated input signal as vision signal VD _sigexport.

Below by the compensation of the burn in detailed description display device 1.First, the method for reference operating time when describing accounting temperature conditions constant with reference to Fig. 6 ~ 11.Then, for being convenient to understand object of the present disclosure, the operation of the benchmark example of not renewal rewards theory time conversion factor is described with reference to Figure 12 ~ 17.Afterwards, the operation of the example of renewal rewards theory time conversion factor is described with reference to figure 2, Figure 18 and Figure 19.

The curve map of the relation between the cumulative operational time that Fig. 6 is schematic illustrations when the vision signal operation making display element based on various gray-scale value and the relative change of the brightness of the display element caused due to rheological parameters' change with time.

Curve map shown in Fig. 6 will be described in detail.By using display device 1 in an initial condition, make to be included in the vision signal VD of first in viewing area to the 6th region based on gray-scale value 50,100,200,300,400 and 500 _sigoperation, and the ratio measuring the brightness after the length of cumulative operational time and rheological parameters' change with time and the brightness under the original state of display element 10 forming this first to the 6th region.The length of cumulative operational time is plotted as the value of transverse axis, and the ratio of the brightness after rheological parameters' change with time and the brightness under the original state of display element 10 being divided into the first to the 6th region is plotted as the value of Z-axis.Because needs are by vision signal VD _siggray-scale value remain on above-mentioned gray-scale value, so make brightness correction unit 110 inoperation shown in Fig. 1, the vision signal VD of these gray-scale values _siggenerated by special circuit and be supplied to signal output apparatus 102, then measuring.

The value of the Z-axis in the curve map shown in Fig. 6 corresponds to factor alpha _tdcand factor alpha _iniratio.As being clear that from described curve map, for the relative change of the brightness of the brightness under original state along with vision signal VD _siggray-scale value increase and increase.Similarly, the relative change for the brightness of the brightness under original state increases along with cumulative operational time increase.

Therefore, the brightness of display element 10 changes the vision signal VD depended on when display element 10 operates _siggray-scale value and the length of running time.Describe when making display element 10 at change vision signal VD below with reference to Fig. 7 _siggray-scale value while operation time rheological parameters' change with time.

The curve map of the relation that Fig. 7 is schematic illustrations between running time and the relative brightness of display element that causes due to rheological parameters' change with time when making display element operate while the gray-scale value changing vision signal change.

Particularly, the curve map shown in Fig. 7 makes display element 10 based on the vision signal VD of gray-scale value 50, gray-scale value 100, gray-scale value 200, gray-scale value 300, gray-scale value 400 and gray-scale value 500 based on working as _sig, operate running time DT respectively by using display device 1 in an initial condition ₁, running time DT ₂, running time DT ₃, running time DT ₄, running time DT ₅with running time DT ₆time data, the length of cumulative operational time is plotted as the value of transverse axis, and is the curve map of the value of Z-axis by the scale of brightness under the original state of the brightness after rheological parameters' change with time and display element 10.As described with reference to figure 6, brightness correction unit 110 inoperation shown in Fig. 1 is made, the vision signal VD of these gray-scale values _siggenerated by special circuit and be supplied to signal output apparatus 102, then measuring.

In the figure 7, Reference numeral PT ₁, PT ₂, PT ₃, PT ₄, PT ₅and PT ₆the value of cumulative operational time when representing that time.Time PT ₆running time DT ₁to running time DT ₆the summation of length.

In the figure 7, RA (PT is used respectively ₁), RA (PT ₂), RA (PT ₃), RA (PT ₄), RA (PT ₅) and RA (PT ₆) represent and PT ₁, PT ₂, PT ₃, PT ₄, PT ₅and PT ₆the value of corresponding Z-axis.In curve map in the figure 7, use reference number C L respectively ₁, CL ₂, CL ₃, CL ₄, CL ₅and CL ₆represent from the time 0 to time PT ₁part, from time PT ₁to time PT ₂part, from PT ₂to time PT ₃part, from time PT ₃to time PT ₄part, from PT ₄to time PT ₅part and from time PT ₅to time PT ₆part.Can say that the curve map shown in Fig. 7 is obtained by the various piece of the curve map shown in suitable connection layout 6.

Fig. 8 is that schematic illustrations uses reference number C L in the figure 7 ₁, CL ₂, CL ₃, CL ₄, CL ₅and CL ₆the sketch of corresponding relation between curve map in each graph parts represented and Fig. 6.

As shown in Figure 8, reference number C L is used in the figure 7 ₁the graph parts represented corresponds to when 1 to RA (PT ₁) Z-axis in scope part when being in the curve map of the gray-scale value 50 in Fig. 6.Use reference number C L ₂the graph parts represented corresponds to as RA (PT ₁) to RA (PT ₂) Z-axis in scope part when being in the curve map of the gray-scale value 100 in Fig. 6.Use reference number C L ₃the graph parts represented corresponds to as RA (PT ₂) to RA (PT ₃) Z-axis in scope part when being in the curve map of the gray-scale value 200 in Fig. 6.

Similarly, reference number C L is used in the figure 7 ₄the graph parts represented corresponds to as RA (PT ₃) to RA (PT ₄) Z-axis in scope part when being in the curve map of the gray-scale value 300 in Fig. 6.Use reference number C L ₅the graph parts represented corresponds to as RA (PT ₄) to RA (PT ₅) Z-axis in scope part when being in the curve map of the gray-scale value 400 in Fig. 6.Use reference number C L ₆the graph parts represented corresponds to as RA (PT ₅) to RA (PT ₆) Z-axis in scope part when being in the curve map of the gray-scale value 500 in Fig. 6.

On the other hand, shown in the figure 7 time PT ₆time display element 10 the rheological parameters' change with time of brightness correspond to and make display element 10 from the time 0 to time PT when hypothesis ₆', based on the vision signal VD of gray-scale value 200 _sigthe rheological parameters' change with time of the brightness of display element 10 during operation.Time PT ₆' represent that the value working as Z-axis is the RA (PT in the curve map of the gray-scale value 200 shown in Fig. 6 ₆) time accumulation reference operating time.

Therefore, when carrying out PT computing time based on the operation history shown in Fig. 7 ₆' value of (accumulation reference operating time) time, can based on time PT ₆' value and the curve of the gray scale 200 shown in Fig. 6 calculate time PT shown in Fig. 7 ₆time display element 10 the rheological parameters' change with time of brightness.

Can based on running time DT shown in the figure 7 ₁to DT ₆respective length and reflecting video signal VD _sigthe pre-determined factor (running time conversion factor) of gray-scale value calculate accumulation reference operating time PT ₆'.Below with reference to Fig. 9 to Figure 11, running time conversion coefficient is described.

Fig. 9 is that schematic illustrations is making display element 10 based on vision signal VD until the relative brightness change of the display element 10 caused due to rheological parameters' change with time reaches _sigcumulative operational time till the determined value " β " of operation and this vision signal VD _siggray-scale value between the curve map of relation.The curve map corresponding with gray-scale value is identical with the curve map shown in Fig. 6.In addition, also 1 > β > 0 is met.

In fig .9, Reference numeral ET _{t1_500}represent the cumulative operational time when the value of Z-axis is " β " under gray-scale value 500, and Reference numeral ET _{t1_400}represent the cumulative operational time when the value of Z-axis is " β " under gray-scale value 400.This point is for Reference numeral ET _{t1_300}, ET _{t1_200}, ET _{t1_100}and ET _{t1_50}also be right.

No matter the value of " β " how, cumulative operational time ET _{t1_500}, ET _{t1_400}, ET _{t1_300}, ET _{t1_200}, ET _{t1_100}and ET _{t1_50}mutual ratio be in fact constant.On the contrary, display element 10 is thought with change service time to meet such condition.

Figure 10 is schematic illustrations by the curve map of the method for the reference operating time of working as when making display element 10 be transformed into the vision signal operation when hypothesis makes display element based on predetermined benchmark gray-scale value (that is, gray-scale value 200) based on running time during operation history operation shown in Fig. 7.

Reference operating time DT shown in Figure 10 ₁', DT ₂', DT ₃', DT ₄', DT ₅' and DT ₆' corresponding to the running time DT shown in Fig. 7 ₁, DT ₂, DT ₃, DT ₄, DT ₅and DT ₆the value be transformed into.

Such as, reference operating time DT ₁' can DT be used ₁'=DT ₁(ET _{t1_200}/ ET _{t1_50}) calculate.(ET _{t1_200}/ ET _{t1_50}) corresponding to the running time conversion factor under gray-scale value 50.

Similarly, reference operating time DT ₂' can DT be used ₂'=DT ₂(ET _{t1_200}/ ET _{t1_100}) calculate.ET _{t1_200}/ ET _{t1_100}corresponding to the running time conversion factor under gray-scale value 100.

Can Calculation Basis running time DT in the same manner as described above ₃', DT ₄', DT ₅' and DT ₆'.

That is, DT can be used respectively ₃(ET _{t1_200}/ ET _{t1_200}), DT ₄(ET _{t1_200}/ ET _{t1_300}), DT ₅(ET _{t1_200}/ ET _{t1_400}) and DT ₆(ET _{t1_200}/ ET _{t1_500}) Calculation Basis running time DT ₃', DT ₄', DT ₅' and DT ₆'.Running time conversion factor under gray-scale value 200,300,400 and 500 is given as (ET _{t1_200}/ ET _{t1_200}), (ET _{t1_200}/ ET _{t1_300}), (ET _{t1_200}/ ET _{t1_400}) and (ET _{t1_200}/ ET _{t1_500}).Can as reference operating time DT ₁', DT ₂', DT ₃', DT ₄', DT ₅' and DT ₆' summation calculate accumulation reference operating time PT ₆'.

Running time conversion factor depends on gray-value variation.Figure 11 is the curve map of the relation between the gray-scale value of diagram vision signal and running time conversion factor.

As mentioned above, the Calculation Basis running time can be carried out by actual operating time being multiplied by running time conversion factor.

For being convenient to understand object of the present disclosure, the operation of the benchmark example of not renewal rewards theory time conversion factor is described below with reference to Figure 12 to Figure 17.

Figure 12 is the block diagram that schematic illustrations is used in the configuration of the brightness correction unit in benchmark example.

Upgrade part except running time conversion factor retainer 113 ' does not comprise running time conversion factor and do not update stored in except running time conversion factor reservoir 113A ', the configuration of the brightness correction unit 110 ' shown in Figure 12 is identical with the brightness correction unit 110 shown in Fig. 2.

Figure 13 is the curve map that schematic illustrations is stored in the data in datum curve reservoir.

Datum curve reservoir 116 shown in Fig. 2 or Figure 12 will represent the function f of the datum curve shown in Figure 13 in advance _rEFbe stored as table.Curve under this datum curve instruction gray-scale value 200 in fig .9.

Figure 14 is the curve map that schematic illustrations is stored in the data in running time conversion factor retainer.

Running time conversion factor retainer 113 ' shown in Figure 12 will represent the function f of the relation shown in Figure 14 in advance _cSCbe stored as table.Its illustrate in fig. 11, at vision signal VD _siggray-scale value and running time conversion factor between relation.

Figure 15 is the schematic diagram that schematic illustrations is stored in the data in accumulation reference operating time reservoir.

Accumulation reference operating time reservoir 114 shown in Fig. 2 or Figure 12 comprises the storage area corresponding with display element 10, be made up of rewritable non-volatile memory device, and store instruction accumulation reference operating time and the data SP (1 be illustrated in fig .15,1) to SP (N, M).Although do not need the operation in benchmark example, accumulation reference operating time reservoir 114 stores the mute display element 10 of instruction _dmythe data AP of cumulative operational time.

Figure 17 is the sketch that schematic illustrations is stored in the data in the grey scale correction values reservoir of gradation correction value holder.

Grey scale correction values reservoir 115B shown in Fig. 2 or Figure 12 comprises the storage area corresponding with display element 10, be made up of recordable memory part, and store the instruction corrected value of gray-scale value and the data LC (1,1) be illustrated in fig. 17 to LC (N, M).

Gamma correction step is comprised, for passing through the operation adjustment input signal vD based on brightness correction unit 110 ' according to the driving method of this benchmark example _siggray-scale value and using calibrated input signal as vision signal VD _sigexport the brightness correcting the display element 10 when showing image on the display panel 20, and this gamma correction step comprises: reference operating time calculation procedure, for the value of Calculation Basis running time, under this reference operating time, when the display element 10 of correspondence is based on vision signal VD _sigduring operation scheduled unit time, the rheological parameters' change with time of the brightness of each display element 10 equals when supposing the vision signal VD of corresponding display element 10 based on predetermined benchmark gray-scale value _sigthe rheological parameters' change with time of the brightness of each display element 10 during operation; Accumulation reference operating time storing step, for storing the accumulation reference operating time obtained about the calculated value of the reference operating time of each display element 10 by accumulation; Grey scale correction values keeps step, for working as corresponding display element 10 under predetermined temperature based on the vision signal VD of predetermined benchmark gray-scale value based on accumulation reference operating time, referential expression _sigthe datum curve of relation during operation between running time of each display element 10 and the rheological parameters' change with time of the brightness of corresponding display element 10, calculate and be used for the corrected value of gray-scale value of rheological parameters' change with time of the brightness compensating each display element 10, and keep the corrected value of the gray-scale value corresponding with each display element 10; And vision signal generation step, correct the input signal vD corresponding with each display element for the corrected value based on gray-scale value _siggray-scale value, and export calibrated input signal as vision signal VD _sig.

Here, below will be described in and instead of in the display device 1 of brightness correction unit 110 with brightness correction unit 110 ', when the original state from display device 1 terminate cumulatively first to (Q-1) frame display and carry out display Q (wherein Q be equal to or greater than 2 natural number) writing process of frame time about the gamma correction step of (n, m) display element 10.

Use vD _{sig (n, m) _ q}and VD _{sig (n, m) _ q}represent (n, m) display element 10 q (wherein q=1,2 ..., Q) input signal vD in frame _sigwith vision signal VD _sig.When display q frame, with SP (n, m) _ _qexpress the data of the accumulation reference operating time representing corresponding with (n, m) display element 10.As mentioned above, Reference numeral T is used _frepresent the time shared by a so-called frame period.In an initial condition, data LC (1 is stored in using data AP with as " 1 " of initial value in advance in advance using being stored in data SP (1,1) as " 0 " of initial value to SP (N, M), 1) in LC (N, M).

In (Q-1) display frame, the reference operating time counter 112 shown in Fig. 2 is based on vision signal VD _{sig (n, m) _ Q-1}carry out reference operating time calculation procedure.

Particularly, reference operating time counter 112 is based on vision signal VD _{sig (n, m) _ Q-1}, carry out computing function value f with reference to running time conversion factor reservoir 113 _cSC(VD _{sig (n, m) _ Q-1}).Reference operating time=T is carried out about (Q-1) display frame _ff _tAC(WPT_ _q-1) f _cSC(VD _{sig (n, m) _ Q-1}) calculating.

Accumulation reference operating time reservoir 114 carries out accumulation reference operating time storing step, and this step stores the reference operating time calculated by reference operating time counter 112 about each display element 10 by accumulation and the accumulation reference operating time obtained.

Particularly, in (Q-1) display frame, the data SP (n, m) before the reference operating time in (Q-1) display frame is added to by accumulation reference operating time reservoir 114 _ _q-2.Particularly, carry out SP (n, m) _ _q-1=SP (n, m) _ _q-2+ T _ff _cSC(VD _{sig (n, m) _ Q-1}) calculating.Correspondingly, by by accumulating the reference operating time calculated by reference operating time counter 112 about each display element 10, the accumulation reference operating time obtained is stored in accumulation reference operating time reservoir 114.

Although do not need the operation in benchmark example, accumulation reference operating time reservoir 114 stores the mute display element 10 of instruction _dmythe data AP of cumulative operational time.Particularly, AP_ is calculated _q-1=AP_ _q-2+ T _fcalculating.Data AP indicates the actual value of the cumulative operational time of display device 1.

Gradation correction value holder 115 carries out grey scale correction values storing step, and this step stores the corrected value of the gray-scale value corresponding with each display element 10.

Figure 16 is the curve map of the operation of the grey scale correction values counter 115A of schematic illustrations gradation correction value holder 115.

Particularly, grey scale correction values counter 115A based on the data SP (n, m) be stored in accumulation reference operating time reservoir 114 _ _q-1, reference data curve reservoir 116 (see Figure 16), carrys out computing function value f _rEF(SP (n, m) _ _q-1).Functional value f _rEF(SP (n, m) _ _q-1) inverse as the corrected value of gray-scale value be stored in the data LC (n, m) of grey scale correction values reservoir 115B _ _q-1in.

Video signal generator 111 carries out vision signal generation step, and this step corrects the input signal vD corresponding with each display element 10 based on the corrected value of gray-scale value _siggray-scale value, and using calibrated input signal as vision signal VD _sigexport.

That is, before immediately Q frame, accumulation reference operating time reservoir 114 store data SP (1,1) _ _q-1to SP (N, M) _ _q-1, and the grey scale correction values reservoir 115B of gradation correction value holder 115 storage data LC (1,1) _ _q-1to LC (N, M) _ _q-1.

Video signal generator 111 reference-input signal vD _{sig (n, m) _ Q}with the data LC (n, m) in grey scale correction values reservoir 115B _ _q-1carry out vision signal VD _{sig (n, m) _ Q}=VD _{sig (n, m) _ Q}lC (n, m) _ _q-1calculating, and by generated vision signal VD _{sig (n, m) _ Q}be fed to signal output apparatus 102.

Then, the display of Q frame is carried out.After this, in (Q+1) frame or its subsequent frame, aforesaid operations is repeated.

According in the driving method of this benchmark example, with reference to conversion factor retainer 113 Calculation Basis running time running time, calculated value is stored as accumulation reference operating time, and calculates the corrected value of gray-scale value based on accumulation reference operating time, reference data curve reservoir 116.Vision signal VD _siggray-scale value be reflected in reference operating time.

Therefore, vision signal VD _sigthe history of gray-scale value be reflected in the accumulation reference operating time of the value that have accumulated reference operating time.Correspondingly, the change of the brightness caused due to rheological parameters' change with time can be compensated.

So far, the operation in the benchmark example of not renewal rewards theory time conversion factor has been described.

In practice, display board 20 is not uniform in running time conversion factor.When being stored in advance in the actual operating time conversion factor that the running time conversion factor in running time conversion factor reservoir 113A ' is different from indicated by display board 20, the precision of compensate for brightness change reduces.In the operation of example 1, due to based on mute display element 10 _dmybrightness change renewal rewards theory time conversion factor, so can compensate for brightness change with the unevenness tackling display board 20.Below by operation during description renewal rewards theory time conversion factor.

Running time conversion factor shown in Fig. 2 upgrades part 113B every the renewal rewards theory schedule time, conversion factor time.That is, running time conversion factor upgrades part 113B such as by one hour, as long as the value of data AP increases, the data AP just with reference to accumulation reference operating time reservoir 114 obtains mute display element 10 from optical sensor 120 _dmymonochrome information.Running time conversion factor upgrades part 113B and passes through the value of datum curve and the mute display element 10 measured _dmyvalue relatively carry out renewal rewards theory time conversion factor.

In example 1, running time conversion factor upgrades the multiple mute display element 10 of part 113B by operating based on different gray-scale value _dmyrunning time and the rheological parameters' change with time of brightness and datum curve f _rEFvalue relatively carry out the value of renewal rewards theory time conversion factor.

Figure 18 is the curve map of the method that the value of mute display element measured compares with the value of datum curve by schematic illustrations.

The mute display element 10 measured will be described in detail below _dmythe comparing of value of value and datum curve.When the value of data AP reach carry out the determined value APT of renewal rewards theory thereon time, running time conversion factor upgrades part 113B and calculates brightness value and mute display element 10 based on the monochrome information from optical sensor 120 _dmythe ratio of brightness value of original state.This ratio corresponds to above-mentioned α _tdc/ α _ini.In figure 18, Reference numeral β is used _{aPT_100}, β _{aPT_200}, β _{aPT_300}, β _{aPT_400}and β _{aPT_500}represent the vision signal VD based on gray-scale value 100,200,300,400 and 500 _dmythe mute display element 10 operated _dmyratio.

Running time conversion factor upgrades part 113B will be stored in the datum curve f in datum curve reservoir 116 _rEFwith β _{aPT_100}, β _{aPT_200}, β _{aPT_300}, β _{aPT_400}and β _{aPT_500}value compare, and when the value of Z-axis is β _{aPT_100}, β _{aPT_200}, β _{aPT_300}, β _{aPT_400}and β _{aPT_500}time Calculation Basis curve f _rEFthe value of transverse axis.Use Reference numeral ET _{aPT_100}, ET _{aPT_200}, ET _{aPT_300}, ET _{aPT_400}and ET _{aPT_500}represent and β _{aPT_100}, β _{aPT_200}, β _{aPT_300}, β _{aPT_400}and β _{aPT_500}the value of transverse axis corresponding to value.

Figure 18 shows the mute display element 10 in gray-scale value 200 times operations _dmyrheological parameters' change with time than datum curve f _rEFslow example.In this case, the rheological parameters' change with time of the brightness of display board 20 is slower than what suppose.Running time conversion factor upgrades part 113B and upgrades this value to reduce running time conversion factor.

Particularly, running time conversion factor upgrades part 113B calculating ET _{aPT_100}/ APT, ET _{aPT_200}/ APT, ET _{aPT_300}/ APT, ET _{aPT_400}/ APT and ET _{aPT_500}the value of/APT.These values are set to the new running time conversion factor under gray-scale value 100,200,300,400 and 500, and are interpolated to determine new function f _{cSC_APT}.By storing this function f in running time conversion factor reservoir 113A _{cSC_APT}, renewal rewards theory time conversion factor.Figure 19 is the curve map that schematic illustrations is stored in the more new data in running time conversion factor retainer.

In example 1, due to based on mute display element 10 _dmyrheological parameters' change with time renewal rewards theory time conversion factor, so the respective difference that can depend on display board 20 is to compensate rheological parameters' change with time.Therefore, more high-precision control can be carried out.

Below set forth display device 1 for monochromatic display device, but also can use colour display device.In this case, such as, when the trend of the rheological parameters' change with time of display element 10 depends on glow color change, only the running time conversion factor retainer 113 shown in Fig. 2 and datum curve reservoir 116 must be provided about often kind of glow color separately.Only must provide mute display element 10 about often kind of glow color separately _dmyand optical sensor.

Below the compensation of burn in display device 1 has been described in detail.In the example 1 that will describe later and example 2, except the burn of (n, m) display element 10 compensate outside the details of operation be similar.For the object of simplified illustration, the operation outside the burn in detail except description (n, m) display element 10 in the later half of expression formula 2 is compensated.

[example 2]

Example 2 also relates to display device according to embodiment of the present disclosure and display-apparatus driving method.

In example 1, based on the mute display element 10 that the vision signal based on different gray-scale value operates _dmymonochrome information carry out renewal rewards theory time conversion factor.On the contrary, in example 2, based on the mute display element 10 that the vision signal based on single gray-scale value operates _dmymonochrome information carry out renewal rewards theory time conversion factor.

Substantially identical with the configuration of the display device according to example 1 according to the configuration of the display device of example 2.Correspondingly, by the overall pattern of conceptual diagram or brightness correction unit that display device is not shown.Except the method difference of renewal rewards theory time conversion factor, equal the driving method according to example 1 according to the driving method of example 2.This description will concentrate on the method for renewal rewards theory time conversion factor.

As shown in Figure 19 of being referenced in example 1, renewal function f _{cSC_APT}indicate by changing function f with constant ratio _cSCvalue and the curve obtained.Therefore, in example 2, by based on this vision signal VD based on single gray-scale value _dmythe mute display element 10 of operation _dmymonochrome information calculate the value of the running time conversion factor in brightness and depend on calculated value pre-determined factor is applied to function f _cSC, renewal rewards theory time conversion factor.

Figure 20 is the curve map of the method that the value of mute display element measured compares with the value of datum curve by schematic illustrations.

In example 2, running time conversion factor upgrades part 113B by based on the mute display element 10 in gray-scale value 200 times operation _dmymonochrome information and the Reference numeral β obtained _{aPT_200}value be stored in datum curve f in datum curve reservoir 116 _rEFcompare, and when the value of Z-axis is β _{aPT_200}time calculated level axle ET _{aPT_200}value.

Function f under gray-scale value 200 _cSCvalue be defined as f _cSC(200) time, by by function f _{cSC_APT}be arranged to (ET _{aP_200}/ APT)/f _cSC(200) f _cSCand by function f _{cSC_APT}be stored in running time conversion factor reservoir 113A and carry out renewal rewards theory time conversion factor.Figure 21 is the curve map that schematic illustrations is stored in the more new data in running time conversion factor reservoir.

In example 2, due to based on the vision signal VD based on single gray-scale value _dmythe mute display element 10 of operation _dmymonochrome information carry out renewal rewards theory time conversion factor, so compared with example 1, can simplify upgrade control.

Can be colour display device according to the display device of example 2.In this case, such as, when the trend of the rheological parameters' change with time of display element 10 depends on glow color change, only the running time conversion factor retainer 113 shown in Fig. 2 and datum curve reservoir 116 must be provided about often kind of glow color separately.Only must provide mute display element 10 about often kind of glow color separately _dmyand optical sensor.

Below with reference to Figure 22, Figure 24 A and Figure 24 B, Figure 25 A and Figure 25 B, Figure 26 A and Figure 26 B, Figure 27 A and Figure 27 B, Figure 28 A and Figure 28 B and Figure 29, the details of the operation outside the burn compensation of (n, m) display element 10 is described.Figure 23 is the timing diagram of the operation of the mute display element of schematic illustrations.Because following description can suitably substitute, so do not describe mute display element 10 _dmydetailed operation.In accompanying drawing or following description, the object illustrated for convenience, video voltage V that will be corresponding with (n, m) display element 10 _{sig (n, m)}be defined as V _{sig_m}.

[period TP (2) _-1] (see Figure 22 and Figure 24 A)

Period TP (2) _-1operation such as before instruction in display frame, and after being the pre-treatment finished, (n, m) display element 10 is in the time period of luminance.That is, based on the drain current I of expression formula 5 ' _ds' be flowing in the luminous component ELP of the display element 10 of (n, m) pixel, and the brightness of the display element 10 of (n, m) pixel has and drain current I _ds' corresponding value.Here, write transistor TR _wbe in OFF state, and driving transistors TR _dbe in ON state.The luminance of (n, m) display element 10 was kept before the horizontal scanning period of the display element 10 immediately starting the in (m+m ') row.

As mentioned above, data line DTL _nbe supplied with reference voltage V _ofswith video voltage V _sigto correspond to each horizontal scanning period.But, write transistor TR _wbe in OFF state.Correspondingly, even as data line DTL _ncurrent potential (voltage) in period TP (2) _-1during middle change, first node ND ₁with Section Point ND ₂current potential also do not change (potential change caused due to the capacitive coupling of capacitor parasitics etc. may be caused in practice, but generally can be left in the basket).This is in period TP (2) ₀in be also right.

Period TP (2) shown in Figure 22 ₀to TP (2) ₆process before finishing and then after finishing luminance, immediately preceding the operation time period of carrying out before next writing process.In period TP (2) ₀to TP (2) ₇in, (n, m) display element 10 is in non-luminescent state substantially.As shown in figure 22, period TP (2) ₅, period TP (2) ₆with period TP (2) ₇be included in m horizontal scanning period H _min.

In period TP (2) ₃with TP (2) ₅in, by reference voltage V _ofsfrom data line DTL _nthrough the write transistor TR of the sweep signal conducting from sweep trace SCL _w, be applied to driving transistors TR _dgrid state under, carry out driving voltage V _cC-Hdriving transistors TR is applied to from power lead PS1 _danother regions and source/drain thus cause driving transistors TR _dthe current potential of another regions and source/drain become and be close to by from reference voltage V _ofsdeduct driving transistors TR _dstarting voltage and the starting voltage Processing for removing of the current potential obtained.

In the following description, set forth at (that is, (m-1) horizontal scanning period H of multiple horizontal scanning period _m-1with m horizontal scanning period H _m) in carry out starting voltage Processing for removing, but this does not limit the disclosure.

In period TP (2) ₁in, by itself and reference voltage V _ofsdifference be greater than driving transistors TR _dthe initialization voltage V of starting voltage _cC-La regions and source/drain of driving transistors is applied to from power lead PS1, and by reference voltage V _ofsfrom data line DTL _nthrough the write transistor TR of the sweep signal conducting from sweep trace SCL _w, be applied to driving transistors TR _dgrid, thus initialization driving transistors TR _dthe current potential of grid and driving transistors TR _dthe current potential of another regions and source/drain.

In fig. 22, period TP (2) is supposed ₁corresponding to (m-2) horizontal scanning period H _m-2in the reference voltage period (wherein by reference voltage V _ofsbe applied to the period of data line DTL), period TP (2) ₃corresponding to (m-1) horizontal scanning period H _m-1in the reference voltage period, and period TP (2) ₅corresponding to m horizontal scanning period H _min the reference voltage period.

Wait below with reference to Figure 22 and describe period TP (2) ₀to period TP (2) ₈in operation.

[period TP (2) ₀] (see Figure 22 and Figure 24 B)

Period TP (2) ₀in operational example in this way from display frame before to the operation of this display frame.That is, period TP (2) ₀(m+m ') the horizontal scanning period H from display frame before _m+m' period at end of beginning (m-3) horizontal scanning period in this display frame.In period TP (2) ₀in, (n, m) display element 10 is in non-luminescent state.In period TP (2) ₀beginning, is applied to power lead PS1 from power supply unit 100 _mvoltage from driving voltage V _cC-Hchange to initialization voltage V _cC-L.As a result, Section Point ND ₂current potential lower than V _cC-L, and between anode electrode reverse voltage being applied to luminous component ELP and cathode electrode, thus luminous component ELP is changed to non-luminescent state.Reduce the first node ND being in floating state ₁(driving transistors TR _dgrid) current potential to follow the tracks of Section Point ND ₂the reduction of current potential.

[period TP (2) ₁] (see Figure 22 and Figure 25 A)

Start (m-2) the horizontal scanning period H in this display frame _m-2.In period TP (2) ₁in, by sweep trace SCL _mchange to high level, and by the write transistor TR of display element 10 _wchange to ON state.Data line DTL is fed to from main signal output circuit 102 _nvoltage be reference voltage V _ofs.As a result, first node ND ₁current potential be V _ofs(0 volt).Due to initialization voltage V _cC-Lby the operation of power supply unit 100 from power lead PS1 _mbe applied to Section Point ND ₂, so Section Point ND ₂current potential be maintained at V _cC-Lon (-10 volts).

Due to first node ND ₁with Section Point ND ₂between potential difference (PD) be 10 volts and driving transistors TR _dstarting voltage V _thit is 3 volts, so driving transistors TR _dbe in ON state.Section Point ND ₂and the potential difference (PD) between the cathode electrode of luminous component ELP is-10 volts, it is not more than the starting voltage V of luminous component ELP _th-EL.Correspondingly, initialization first node ND ₁current potential and Section Point ND ₂current potential.

[period TP (2) ₂] (see Figure 22 and Figure 25 B)

In period TP (2) ₂, sweep trace SCL _mbe changed to low level.The write transistor TR of display element 10 _wchange to OFF state.First node ND ₁with Section Point ND ₂current potential be substantially maintained at before state under.

[period TP (2) ₃] (see Figure 22 and Figure 26 A)

In period TP (2) ₃in, carry out the first starting voltage Processing for removing.Sweep trace SCL _mbe changed to the write transistor TR that high level carrys out conducting display element 10 _w.Data line DTL is fed to from main signal output circuit 102 _nvoltage be reference voltage V _ofs.First node ND ₁current potential be V _ofs(0 volt).

Power lead PS1 is fed to from power supply unit 100 _mvoltage be switched to voltage V _cC-Lto driving voltage V _cC-H.As a result, first node ND ₁current potential do not change (keep V _ofs, but Section Point ND=0) ₂current potential be changed to by from reference voltage V _ofssubtract driving transistors TR _dstarting voltage V _thand the current potential obtained.That is, Section Point ND ₂current potential be raised.

When period TP (2) ₃during long enough, driving transistors TR _dgrid and another regions and source/drain between potential difference (PD) reach V _th, and driving transistors TR _dbe changed to OFF state.That is, Section Point ND ₂current potential become close to (V _ofs-V _th) and finally become (V _ofs-V _th).In example in fig. 22, period TP (2) ₃curtailment to change Section Point ND ₂current potential, and in period TP (2) ₃end Section Point ND ₂current potential reach and meet relation V _cC-L< V ₁< (V _ofs-V _th) certain current potential V ₁.

[period TP (2) ₄] (see Figure 22 and Figure 26 B)

In period TP (2) ₄in, sweep trace SCL _mbe changed to low level to end the write transistor TR of display element 10 _w.As a result, first node ND ₁be in floating state.

Due to driving voltage V _cC-Hdriving transistors TR is applied to from power supply unit 100 _da regions and source/drain, so Section Point ND ₂current potential from current potential V ₁rise to certain current potential V ₂.On the other hand, due to driving transistors TR _dgrid be in floating state and there is capacitor C ₁, so at driving transistors TR _dgrid in bootstrapping operation occur.Correspondingly, first node ND ₁current potential rise to follow the tracks of Section Point ND ₂potential change.

As period TP (2) ₅in the prerequisite of operation, in period TP (2) ₅beginning Section Point ND ₂current potential should lower than (V _ofs-V _th).Period TP (2) ₄length be substantially specified to the V that satisfies condition ₂< (V _ofs-L-V _th).

[period TP (2) ₅] (see Figure 22 and Figure 27 A and Figure 27 B)

In period TP (2) ₅in, carry out the second starting voltage Processing for removing.By from sweep trace SCL _mthe write transistor TR of sweep signal conducting display element 10 _w.Data line DTL is fed to from signal output apparatus 102 _nvoltage be reference voltage V _ofs.First node ND ₁current potential again turn back to V from the current potential risen due to bootstrapping operation _ofs(0 volt) (see Figure 27 A).

Here, c is used ₁represent capacitor C ₁value, and use c _eLrepresent the capacitor C of luminous component ELP _eLvalue.Use c _gsrepresent driving transistors TR _dgrid and another regions and source/drain between the value of capacitor parasitics.When using Reference numeral c _arepresent first node ND ₁with Section Point ND ₂between electric capacity time, c _a=c ₁+ c _gsset up.When using Reference numeral c _brepresent Section Point ND ₂and c during electric capacity between second source line PS2 _b=c _eLset up.Building-out condenser can parallel join to the two ends of luminous component ELP, but in this case, the electric capacity of building-out condenser is added to c _b.

As first node ND ₁potential change time, first node ND ₁with Section Point ND ₂between potential difference (PD) change.That is, based on first node ND ₁with Section Point ND ₂between electric capacity and Section Point ND ₂and the capacitance profile between second source line PS2 is based on first node ND ₁the electric charge of potential change.But, c on duty _b(=c _eL) ratio c _a(=c ₁+ c _gs) enough large time, Section Point ND ₂potential change very little.Usually, the capacitor C of luminous component ELP _eLvalue c _eLbe greater than capacitor C ₁value c ₁with driving transistors TR _dthe value c of capacitor parasitics _gs.In the following description, do not consider by first node ND ₁the Section Point ND that causes of potential change ₂potential change.In the driving timing figure shown in Figure 22, do not consider by first node ND ₁the Section Point ND that causes of potential change ₂potential change.

Due to from power supply unit 100 by driving voltage V _cC-Hbe applied to driving transistors TR _da regions and source/drain, so Section Point ND ₂potential change to by from reference voltage V _ofsdeduct driving transistors TR _dstarting voltage V _thand the current potential obtained.That is, Section Point ND ₂current potential from current potential V ₂rise and change to from reference voltage V _ofsdeduct driving transistors TR _dstarting voltage V _thand the current potential obtained.As driving transistors TR _dgrid and another regions and source/drain between potential difference (PD) reach V _thtime, driving transistors TR _dcut-off (see Figure 27 B).In this state, Section Point ND ₂current potential close to (V _ofs-V _th).Here, when expression formula 2 is guaranteed, that is, when selecting and determine that current potential meets expression formula 2, luminous component ELP is not luminous.

(V _Ofs-V _th)＜(V _th-EL+V _Cat)...(2)

In period TP (2) ₅in, Section Point ND ₂current potential finally reach (V _ofs-V _th).That is, driving transistors TR is only depended on _dstarting voltage V _thand reference voltage V _ofsdetermine Section Point ND ₂current potential.The current potential of Section Point is independent of the starting voltage V of luminous component ELP _th-EL.In period TP (2) ₅end, write transistor TR _wbased on from sweep trace SCL _msweep signal and change to OFF state from ON state.

[period TP (2) ₆] (see Figure 22 and Figure 28 A)

At write transistor TR _wunder the state remaining on OFF state, video voltage V _{sig_m}replace reference voltage V _ofsand be fed to data line DTL from signal output apparatus 102 _none end.When in period TP (2) ₅driving transistors TR _dwhen being in OFF state, first node ND ₁with Section Point ND ₂current potential practice on do not change (practice may cause the potential change caused due to the capacitive coupling of capacitor parasitics etc., but usually can ignore).When in period TP (2) ₅in driving transistors TR in the starting voltage Processing for removing that carries out _dwhen not reaching OFF state, in period TP (2) ₆in cause bootstrapping operation, therefore first node ND ₁with Section Point ND ₂current potential slightly rise.

[period TP (2) ₇] (see Figure 22 and Figure 28 B)

In period TP (2) ₇in, the write transistor TR of display element 10 _wby from sweep trace SCL _msweep signal and be changed to ON state.By video voltage V _{sig_m}from driving transistors DTL _nbe applied to write transistor TR _wgrid.

In above-mentioned writing process, by driving voltage V _cC-Hdriving transistors TR is applied to from power supply unit 100 _da regions and source/drain state under, by video voltage V _sigbe applied to driving transistors TR _dgrid.Correspondingly, as shown in figure 22, the Section Point ND in display element 10 ₂current potential in period TP (2) ₇middle change.Particularly, Section Point ND ₂current potential rise.The increment of current potential is represented with Reference numeral Δ V.

When with V _grepresent driving transistors TR _dgrid (first node ND ₁) current potential and use V _srepresent driving transistors TR _danother regions and source/drain (Section Point ND ₂) current potential time, V _gvalue and V _svalue as follows, and do not consider Section Point ND ₂the rising of current potential.First node ND ₁with Section Point ND ₂between potential difference (PD), that is, driving transistors TR _dgrid and be used as source region another regions and source/drain between potential difference (PD) V _gscan express by expression formula 3.

V _g＝V _{Sig_m}

V _s≈V _Ofs-V _th

V _gs≈V _{Sig_m}-(V _Ofs-V _th)...(3)

That is, at driving transistors TR _don the V that obtains in writing process _gsonly depend on the video voltage V of the brightness for controlling luminous component ELP _{sig_m}, driving transistors TR _dstarting voltage V _thand reference voltage V _ofs.V _gsindependent of the starting voltage V of luminous component ELP _th-EL.

Below Section Point ND will be described ₂the increment (Δ V) of current potential.According in the driving method of example 1 or example 2, by driving voltage V _cC-Hbe applied to the driving transistors TR of display element 10 _da regions and source/drain state under, carry out writing process.Correspondingly, come together to carry out the driving transistors TR changing display element 10 _dthe mobility correction process of current potential of another regions and source/drain.

When forming driving transistors TR with thin film transistor (TFT) etc. _dtime, be difficult to the unevenness avoiding mobility [mu] between transistor.Correspondingly, even when having the video voltage V of identical value _sigbe applied to multiple driving transistors TR of the unevenness with mobility [mu] _dgrid time, there is the driving transistors TR of large mobility [mu] _dthe drain current I of middle flowing _dswith there is the driving transistors TR of little mobility [mu] _dthe drain current I of middle flowing _dsthere is difference.When such difference occurs, destroy the screen consistance of display device 1.

In above-mentioned driving method, at driving transistors TR _da regions and source/drain be supplied with driving voltage V from power supply unit 100 _cC-Hstate under, by video voltage V _sigbe applied to driving transistors TR _dgrid.Correspondingly, as shown in figure 22, Section Point ND ₂current potential rise in writing process.As driving transistors TR _dmobility [mu] very large time, driving transistors TR _danother regions and source/drain in current potential (that is, Section Point ND ₂current potential) increment Delta V (potential correction value) increase.On the contrary, as driving transistors TR _dthe value of mobility [mu] very little time, driving transistors TR _danother regions and source/drain in current potential increment Delta V reduce.Here, driving transistors TR _dgrid and be used as source region another regions and source/drain between potential difference (PD) V _gsexpression formula 4 is improved to from expression formula 3.

V _gs≈V _{Sig_m}-(V _Ofs-V _th)-ΔV...(4)

The design of display element 10 or display device 1 can be depended on to determine that the length of sweep signal period (writes video voltage V wherein _sig).Suppose that the length of sweep signal period is specified to make at that time at driving transistors TR _danother regions and source/drain in current potential (V _ofs-V _th+ Δ V) meet expression formula 2 '.

In display element 10, luminous component ELP is in period TP (2) ₇in not luminous.By this mobility correction process, carry out coefficient k (≡ (1/2) (W/L) C simultaneously _ox) depart from.

(V _Ofs-V _th+ΔV)＜(V _th-EL+V _Cat)...(2’)

[period TP (2) ₈] (see Figure 22 and Figure 29)

Keep driving transistors TR _da regions and source/drain be supplied with driving voltage V from power supply unit 100 _cC-Hstate.In display device 10, by writing process will with video voltage V _{sig_m}corresponding store voltages is at capacitor C ₁in.Because the supply of the sweep signal from sweep trace terminates, so write transistor TR _wbe cut off.Correspondingly, by stopping video voltage V _{sig_m}to driving transistors TR _dthe applying of grid, be stored in capacitor C with by writing process ₁in electric current corresponding to the value of voltage via driving transistors TR _dand flow in luminous component ELP, thus luminous component ELP is luminous.

The operation of display element 10 will be described in more detail below.Keep driving voltage V _cC-Hdriving transistors TR is fed to from power supply unit 100 _dthe state of a regions and source/drain, and first node ND ₁with data line DTL _nelectricity is separated.Correspondingly, as a result, Section Point ND ₂current potential rise.

As mentioned above, due to driving transistors TR _dgrid be in floating state, and capacitor C ₁exist, so the phenomenon identical with the phenomenon occurred in so-called boostrap circuit occurs in driving transistors TR _dgrid in, and first node ND ₁current potential also rise.As a result, driving transistors TR is kept _dgrid and be used as source region another regions and source/drain between potential difference (PD) V _gsfor the value expressed by expression formula 4.

Due to Section Point ND ₂current potential rise and become and be greater than (V _th-EL+ V _cat), launch so luminous component ELP starts its light.Now, the electric current owing to flowing in luminous component ELP is from driving transistors TR _ddrain region flow to the drain current I of source region _ds, so this electric current can be expressed by expression formula 1.Here, in expression formula 1 and 4, expression formula 1 can be modified to expression formula 5.

I _ds＝k·μ·(V _{Sig_m}-V _Ofs-ΔV) ²...(5)

Therefore, when by reference voltage V _ofswhen being set to 0 volt, the electric current I flowed in luminous component ELP _dswith the video voltage V passed through from the brightness for controlling luminous component ELP _{sig_m}value in deduct based on driving transistors TR _dthe value of potential correction value Δ V of mobility [mu] and the value obtained square proportional.In other words, the electric current I flowed in luminous component ELP _dsdo not rely on the starting voltage V of luminous component ELP _th-ELand driving transistors TR _dstarting voltage V _th.That is, the luminous intensity (brightness) of luminous component ELP is not by the starting voltage V of luminous component ELP _th-ELand driving transistors TR _dstarting voltage V _thimpact.The brightness of (n, m) display element 10 has and electric current I _dscorresponding value.

In addition, as driving transistors TR _dwhen having larger mobility [mu], potential correction value Δ V increases, thus expression formula 4 left end V _gsvalue reduce.Correspondingly, in expression formula 5, due to (V _{sig_m}-V _ofs-Δ V) ²worthwhile mobility [mu] value increase time reduce, so can correct due to driving transistors TR _dthe unevenness (unevenness of k) of mobility [mu] and the drain current I caused _dsunevenness.As a result, the unevenness of the brightness of the luminous component ELP caused due to the unevenness (with the unevenness of k) of mobility [mu] can be corrected.

The luminance of luminous component ELP is remained to (m+m '-1) the horizontal scanning period.The end of (m+m '-1) horizontal scanning period corresponds to period TP (2) _-1end.Here, " m " ' meets relation 1 < m ' < M, and is value predetermined in display device 1.In other words, from period TP (2) ₈beginning to (m+m ') horizontal scanning period H immediately preceding _{m+m '}front wheel driving luminous component ELP, and this period be used as light-emitting period.

Although describe the disclosure with reference to preferred exemplary, the disclosure is not limited to this example.The configuration of the structure of the display device be described herein, manufacture the method for display device step and drive the step of method of display device to be only example, and can suitably to modify.

Such as, driving transistors TR has been set forth in this example _dit is n channel-type.But, as driving transistors TR _dwhen being p channel-type, only need the anode electrode and the cathode electrode that exchange luminous component ELP.In this configuration, owing to changing the direction of drain current flows, so the value of the voltage being fed to power lead PS1 etc. suitably can be changed.

As shown in figure 30, the driving circuit 11 of display element 10 can comprise and is connected to first node ND ₁transistor (the first transistor TR ₁).At this first transistor TR ₁in, a regions and source/drain is supplied with reference voltage V _ofs, and another regions and source/drain is connected to first node ND ₁.Control signal from the first transistor control circuit 103 is applied to the first transistor TR via the first transistor control line AZ1 ₁grid, to control the first transistor TR ₁oN/OFF state.Correspondingly, first node ND can be set ₁current potential.

Except the first transistor TR ₁outward, the driving circuit 11 of display element 10 can also comprise other transistors.Figure 31 shows and wherein additionally provides transistor seconds TR ₂with third transistor TR ₃configuration.At transistor seconds TR ₂in, a regions and source/drain is supplied with initialization voltage V _cC-L, and another regions and source/drain is connected to Section Point ND ₂.Control signal from transistor seconds control circuit 104 is applied to transistor seconds TR via transistor seconds control line AZ2 ₂grid, to control transistor seconds TR ₂oN/OFF state.Correspondingly, can initialization Section Point ND ₂current potential.Third transistor TR ₃be connected to driving transistors TR _da regions and source/drain and power lead PS1 between, and be applied to third transistor TR from the control signal of third transistor control circuit 105 via third transistor control line CL ₃grid.

The disclosure comprises the theme of theme disclosed in the Japanese Priority Patent Application JP2010-279004 that relates on Dec 15th, 2010 and submit in Japan Office, and its full content is incorporated in this by reference.

It should be appreciated by those skilled in the art, depend on designing requirement and other factors, can occur various improvement, combination, regardless of combination with change, as long as they be in appended claims or its equivalent scope within.

Claims

1. a display device, comprising:

Display board, it comprises the display element with current drive-type luminous component and this display board shows image based on vision signal; And

Brightness correction unit, it corrects the brightness of described display element by correcting the gray-scale value of input signal and exporting calibrated input signal as vision signal when working as display board display image,

Wherein this brightness correction unit comprises

Running time conversion factor retainer, it stores as running time conversion factor until the rheological parameters' change with time of brightness reaches the value of the running time of the determined value making each display element operate based on the vision signal of various gray-scale value and until the rheological parameters' change with time of brightness reaches the ratio of the value of the running time of this determined value making each display element operate based on the vision signal of predetermined benchmark gray-scale value

Reference operating time counter, it carrys out the value of Calculation Basis running time by the value value of the running time conversion factor corresponding with the gray-scale value of vision signal being multiplied by the unit interval, in this reference operating time, when the display element of correspondence to equal the rheological parameters' change with time of the brightness of each display element when display element corresponding to hypothesis operates based on the vision signal of this predetermined benchmark gray-scale value based on the rheological parameters' change with time of brightness of each display element during vision signal operation scheduled unit time

Accumulation reference operating time reservoir, its accumulation reference operating time storing the value by accumulating the reference operating time calculated by reference operating time counter about each display element and obtain,

Datum curve reservoir, it stores the datum curve of the relation represented between the running time of each display element and the rheological parameters' change with time of the brightness of the display element corresponding when corresponding display element operates based on the vision signal of predetermined benchmark gray-scale value,

Gradation correction value holder, it calculates the grey scale correction values of the rheological parameters' change with time of the brightness for compensating each display element with reference to accumulation reference operating time reservoir and datum curve reservoir, and stores the grey scale correction values corresponding with each display element, and

Video signal generator, it corrects the gray-scale value of the input signal corresponding with each display element based on the grey scale correction values be stored in gradation correction value holder, and exports calibrated input signal as vision signal,

Wherein this display board comprises the mute display element not making image display, and

This running time conversion factor retainer comprises running time conversion factor renewal part, for by the value of datum curve is compared to come renewal rewards theory time conversion factor with the rheological parameters' change with time of the running time when this mute display element operates based on the vision signal of predetermined gray-scale value and brightness.

2. display device according to claim 1, wherein this running time conversion factor upgrades part every the renewal rewards theory schedule time, conversion factor time.

3. display device according to claim 2, wherein this running time conversion factor upgrades part by the value of datum curve being compared from the running time of multiple mute display element operated based on different gray-scale value and the rheological parameters' change with time of brightness, carrys out the value of renewal rewards theory time conversion factor.

4. display device according to claim 2, wherein this running time conversion factor upgrades part by the value of datum curve being compared with the running time of mute display element operated based on single gray-scale value and the rheological parameters' change with time of brightness, carrys out the value of renewal rewards theory time conversion factor.

5. display device according to claim 1, wherein this luminous component is formed by organic electroluminescent part.

6. a display device, comprising:

Display board, it comprises the display element that is arranged in wherein and based on vision signal display image; And

Correcting unit, it corrects the gray-scale value of input signal and exports calibrated input signal as vision signal,

Wherein this correcting unit comprises

Factor retainer, it stores as the factor until the rheological parameters' change with time of brightness reaches the value of the running time of the determined value making each display element operate based on the vision signal of various gray-scale value and until the rheological parameters' change with time of brightness reaches the ratio of the value of the running time of this determined value making each display element operate based on the vision signal of predetermined benchmark gray-scale value

Counter, its value based on the Summing Factor unit interval corresponding with gray-scale value carrys out the value of Calculation Basis running time,

Time reservoir, it stores the value of the reference operating time by accumulating each display element and the accumulation reference operating time that obtains,

Reservoir, its storage list is shown in the datum curve of the relation between the running time of each display element under predetermined benchmark gray-scale value and the rheological parameters' change with time of brightness,

Corrected value retainer, it calculates grey scale correction values based on accumulation reference operating time and datum curve, and

Maker, it corrects the gray-scale value of input signal based on this grey scale correction values,

This factor retainer comprises renewal part, for upgrading this factor by being compared mute to datum curve and this running time of display element and the rheological parameters' change with time of brightness.

7. display device according to claim 6, wherein this renewal part is by relatively upgrading this factor by the value of datum curve from the running time of multiple mute display element operated based on different gray-scale value and the rheological parameters' change with time of brightness.

8. display device according to claim 6, wherein this renewal part is by comparing with the running time of mute display element operated based on single gray-scale value and the rheological parameters' change with time of brightness the value upgrading this factor by the value of datum curve.